Two comments:

1) I put a m-20 air/oil separator on my 540 - it does a great job reducing
blowby and keeping the belly clean

2) On my 540 the dip stick has a gasket that fits into the top of the oil
check neck. As the dipstick is inserted it pushes the oil down in the check
tube, making the reading about a qt. low. If I remove the gasket and check,
or check after a few hours I get an accurate reading on the amount of oil in
the engine. So, if I fill to 8 qts, which is what my engine can hold, I'll
actually have closer to 9 qts in the engine.

Michael



"Jay Honeck" wrote in message
news:1EWlb.10391$Fm2.7701@attbi_s04...
...why our Lycoming engines call for 12 (or 8) quarts of oil, when they
blow
out anything over 8 (or 6) quarts?

My old A&P, a real gray head with decades of aviation experience,
mentioned
the reason to me in conversation today. Here's the poop:

When Lycoming was certifying these engines, they had to prove that they
could operate them for "x" number of hours at full throttle. (The number
bandied about was in the hundreds of hours, but no one knew for sure.)
Lycoming was not allowed to add oil to the engine during this
certification
operation.

Obviously, in order to run at such high power settings for so long, you're
gonna need a lot of oil. Thus, the sump on my O-540 was designed to hold
12
quarts, while the sump on my old O-320 held 8 quarts. This ensured that
they would pass the certification test.

However, since they were certified with these over-sized oil sumps, that
became the only way they could be built and sold. This despite the fact
that anything over 8 and 6 quarts, respectively, ends up painting the
belly
of our planes in normal operation...

So now you know...the *rest* of the story.... ;-)
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"